A secure execution environment may utilize a monotonic counter to protect against replay attacks. For monotonic counters whose values are incremented, once the count value changes to a higher number, it should not subsequently exhibit a lower value.
It is an important feature of a monotonic counter that it maintains its value across power cycle events so that a replay attack that results in a power cycle event may not alter the monotonic counter.
There is a need in the art for improved techniques for maintaining monotonic counters to protect from replay attacks.